At least several of the seven suspects arrested in connection with the ambushing and killing of two Louisana deputies and the wounding of two others have been linked to the sovereign citizen movement, officials said today.

The suspects were arrested after a shootout early Thursday morning at a trailer park outside New Orleans, where the two deputies were killed. The two had gone to the trailer park in pursuit of suspects from an earlier incident in which two other deputies were shot and wounded.

The gunmen first opened fire on deputies patrolling a parking lot near a steel plant and oil refinery in LaPlace, La., around 5 a.m. CT., according to St. John the Baptist Sheriff Mike Tregre.

Deputies Brandon Brandon Neilsen, 34, and Jeremy Triche, 28, were "ambushed" by at least three men inside a trailer home, one of whom exited the back of the home with an assault-style weapon.

That gunman "ambushed my two officers," Tregre said.

More than 20 shots were fired between the two locations, from multiple weapons, suggesting a large-scale and sustained shootout.

Sovereign citizens believe any form of government is illegitimate and the only law is the one they create, said Brad Garrett, former FBI agent and ABC News consultant.

"Because they believe in particular law enforcement is not legitimate, they can be quite violent. Since 2000, they have linked at [least] six law enforcement deaths to sovereign citizens," Garrett said.

The seven were all charged in connection with the shooting of one of the deputies who was wounded, as investigators attempt to determine exactly what happened Thursday.

Arrested as accessories after the fact were 37-year-old Chanel Skains and 23-year-old Britney Keith. Authorities listed all as being from LaPlace, about 25 miles west of New Orleans.

Joekel and Brian Smith are in a hospital with gunshot wounds and will be put in jail when they are released. The others were in jail with bonds ranging from $350,000 to $750,000

The sovereign citizens movement has been labeled a domestic terrorism organization by the FBI.

"The FBI are very concerned about them, both from a violent standpoint and also from a white collar crime standpoint," Garrett said.

The sovereign citizen movement has its roots in right-wing anarchist ideology that originated with a group called the Posse Comitatus in the 1970s, according to the Anti-Defamation League.

Along with violence, the ADL said members of the sovereign citizen movement have been known to enage in "paper terrorism," using "fraudulent legal documents and filings, as well as the misuse of legitimate documents and filings, in order to intimidate, harass and coerce public officials, law enforcement officers and private citizens."